Synergistic anti-human immunodeficiency virus type 1 effect of hydroxamate compounds with 2',3'-dideoxyinosine in infected resting human lymphocytes.

The cellular models generally used in the in vitro evaluation of anti-human immunodeficiency virus compounds are dividing cells. A model constituted by resting lymphocytes may more accurately reflect a drug's future efficacy in humans, since viral DNA synthesis is known to take place in quiescent cells, creating a reservoir of infected cells awaiting activation to complete their viral replication cycle and to produce infectious virions. We report here the activity of 3'-azido-3'-deoxythymidine, 2',3'-dideoxyinosine, 2',3'-dideoxycytidine, and two hydroxamates, D-aspartic acid beta-hydroxamate and hydroxycarbamate (hydroxyurea), alone and in various combinations, in an in vitro model based on resting lymphocytes. In our model, resting peripheral blood lymphocytes were infected with human immunodeficiency virus type 1 and treated with drugs for 7 days, at which time drugs were removed and the cells were activated by phytohemagglutinin. We show that under these conditions 3'-azido-3'-deoxythymidine, 2',3'-dideoxyinosine, and 2',3'-dideoxycytidine, alone or in combination, neither fully inhibit viral production nor protect lymphocytes from the cytopathic effect of viral replication, at concentrations corresponding to the peak plasma levels observed in a typical treatment schedule in humans. In contrast, we report the synergistic effect of treatment by each hydroxamate with 2',3'-dideoxyinosine of infected resting lymphocytes, resulting in the total suppression of viral production, total protection against the cytopathic effect induced by viral replication, and no effect on the ability of the cells to replicate in this cell culture system.

当前用于抗人类免疫缺陷病毒（human immunodeficiency virus，HIV）化合物体外评价的细胞模型，通常以增殖型细胞为主。而采用静息淋巴细胞构建的模型，或可更精准地预测药物在人体内的未来疗效——已知病毒DNA合成可发生于静息细胞中，由此形成受感染细胞的储存库，这些细胞需等待激活信号，方能完成病毒复制周期并释放感染性病毒粒子。本研究基于静息淋巴细胞构建的体外模型，评估了3'-叠氮-3'-脱氧胸苷、2',3'-二脱氧肌苷、2',3'-二脱氧胞苷，以及两种羟肟酸类化合物——D-天冬氨酸β-羟肟酸与羟基氨基甲酸酯（羟基脲）——单独或联合使用时的抗病毒活性。在本模型中，研究者将静息外周血淋巴细胞感染人类免疫缺陷病毒1型（HIV-1）后，施以药物处理7天；随后移除药物，通过植物血凝素（phytohemagglutinin，PHA）激活细胞。研究结果显示，在该实验条件下，当药物浓度达到人体典型治疗方案中的血浆峰浓度时，3'-叠氮-3'-脱氧胸苷、2',3'-二脱氧肌苷与2',3'-二脱氧胞苷无论单独使用还是联合给药，均无法完全抑制病毒产生，亦无法保护淋巴细胞免受病毒复制引发的细胞病变效应。与之形成鲜明对比的是，本研究发现两种羟肟酸类化合物分别与2',3'-二脱氧肌苷联合给药时，对感染的静息淋巴细胞可产生协同治疗效果：可完全抑制病毒产生、全面抵御病毒复制诱导的细胞病变效应，且对该细胞培养体系中细胞的增殖能力无不良影响。